Commercial food service equipment is often supported upon a floor by legs or casters. Most equipment in commercial kitchens is set to a common work height. Adjustable legs and leveling devices are used to allow for height adjustments to achieve a common height regardless of factory preset heights. Height adjustments are also needed where the floor is not level or even.
Casters are usually not adjustable in height. Those few that are normally require different mountings than those for the fixed legs or feet that they replace. For safety these must be designed so that a leg or caster may not come off during adjustment. These thus have tended to require rather complex machined adjustment components as exemplified by that shown in U.S. Pat. No. Des 334,136.
In addition, food service equipment often needs to be adopted to either a mobile or immobile configuration at installation. For example, pizza ovens installed in a pizzeria normally have fixed legs while those installed in a convention center have casters for relocation from time to time. Ease of convertibility without the need for change in the equipment's legs or leg sockets is thus desirable.
A problem with food service equipment is that these legs have typically been made of zinc die casting alloys. These alloys have become very expensive. As such, legs have been designed which are made in large part of plastic materials. As shown in FIG. 1, these legs A have a leg portion B with a central stud C and a foot portion D with a central nut E press fitted in the plastic foot and rotatable along the stud. The drawback of these plastic legs that mimic metal leg dimensions is that they do not bear well with side loading and they do not withstand creep deformation. Typical failures occur in the foot area where a metal load bearing nut deforms the plastic and fails the leg.
Side loads occur when a piece of equipment is slid upon the floor and it encounters a sudden stop, as when the foot hits a seam in the floor or when equipment is tilted on its end. This can cause a twist of the conventional nut on its longitudinal axis within the plastic foot, thereby forcing the nut into the plastic or barreling the foot causing it to become unrotatable along the stud.
Accordingly, it is seen that a need remains for height adjustable supports for food service equipment of more economical yet sturdy construction. It is to the provision of such that the present invention is primarily directed.